In accordance with one aspect of the present invention, an omnidirectional antenna comprises a conductiver plate and a resonator. The resonator is positioned adjacent to the conductive plate and comprises a dielectric substrate having a top conductive plate and a bottom conductive plate, wherein the bottom conductive plate provides a ground plane for the resonator and wherein the top conductive plate is shorted to the bottom conductive plate at a first end of the dielectric substrate and open at a second end of the dielectric substrate, a resonator feed located between the first and second ends of the dielectric substrate, a first resonator ground connected to the bottom conductive plate and having a location which is distal to the first end of the dielectric substrate, and a second resonator ground connected to the top conductive plate and to the bottom conductive plate and having a location which is proximal to the first end of the dielectric substrate, wherein the first resonator ground is connected to the conductive plate for suppressing undesirable resonator resonance, and the second resonator ground is connected to the conductive plate for controlling a radiation pattern of the resonator to produce a substantially omnidirectional antenna beam pattern.
In accordance with another aspect of the present invention, an omnidirectional antenna for a receiving device comprises a substrate having a first metallization layer which connects components for a receiver, and at least a second metallization layer which establishes a receiver ground plane, and a resonator. The resonator is positioned adjacent to the substrate and comprises a dielectric substrate having a top conductive plate and a bottom conductive plate, wherein the bottom conductive plate provides a ground plane for the resonator and wherein the top conductive plate is shorted to the bottom conductive plate at a first end of the dielectric substrate and open at a second end of the dielectric substrate. A resonator feed is coupled to the receiver and has a location between the first and second ends of the dielectric substrate and provides an intercepted signal to the receiver. A first resonator ground is connected to the bottom conductive plate and has a location which is distal to the first end of the dielectric substrate, and a second resonator ground is connected to the top conductive plate and to the bottom conductive plate and has a location which is proximal to the first end of the dielectric substrate, wherein the first resonator ground is connected to the receiver ground plane and suppresses undesirable resonator resonance, and the second resonator ground is connected to the receiver ground plane and controls a radiation pattern of the resonator to produce a substantially omnidirectional antenna beam pattern.
In accordance with another aspect of the present invention, a portable communication device comprises an omnidirectional antenna, a receiver, a decoder and an alerting device. The omnidirectional antenna comprises a substrate which has a first metallization layer, and at least a second metallization layer which establishes a receiver ground plane and a resonator. The resonator is positioned adjacent to the substrate and comprises a dielectric substrate which has a top conductive plate and a bottom conductive plate, wherein the bottom conductive plate provides a ground plane for the resonator and wherein the top conductive plate is shorted to the bottom conductive plate at a first end of the dielectric substrate and open at a second end of the dielectric substrate. A resonator feed is location between the first and second ends of the dielectric substrate and provides an intercepted message signal including an address. A first resonator ground is connected to the bottom conductive plate has a location distal to the first end of the dielectric substrate, and a second resonator ground is connected to the top conductive plate and to the bottom conductive plate and has a location proximal to the first end of the dielectric substrate, wherein the first resonator ground is connected to the receiver ground plane for suppressing undesirable resonator resonance, and the second resonator ground is connected to the receiver ground plane for controlling a radiation pattern of the resonator to produce a substantially omnidirectional antenna beam pattern. The receiver is interconnected by the first metallization layer and coupled to the resonator feed and receives and demodulates the intercepted message signal including the address by the omnidirectional antenna. The decoder is interconnected by the first metallization layer and is coupled to receiver and decodes the address received, and generates an alert control signal in response to the address matching a predetermined address. The alerting device is interconnected by the first metallization layer and is responsive to the alert control signal for alerting a user of a message.
In accordance with yet another aspect of the present invention, a transmitting device comprises a radio wave transmitter for transmitting communication signals and an omnidirectional antenna which is coupled to the radio wave transmitter and launches the communication signals for transmission. The omnidirectional antenna comprises a conductive plate, and a resonator. The resonator is positioned adjacent to the conductive plate and comprises a dielectric substrate which has a top conductive plate and a bottom conductive plate, wherein the bottom conductive plate provides a ground plane for the resonator and wherein the top conductive plate is shorted to the bottom conductive plate at a first end of the dielectric substrate and open at a second end of the dielectric substrate. A resonator feed is located between the first and second ends of the dielectric substrate and is coupled to the radio wave transmitter and receives the communication signals to be launched. A first resonator ground is connected to the bottom conductive plate and positioned distal to the first end of the dielectric substrate, and a second resonator ground is connected to the top conductive plate and to the bottom conductive plate and is positioned proximal to the first end of the dielectric substrate, wherein the first resonator ground is connected to the conductive plate and suppresses undesirable resonator resonance, and the second resonator ground is connected to the conductive plate and controls a radiation pattern of the omnidirectional antenna to launch a substantially omnidirectional antenna beam.